Do you use ASSM (Automatic Segment Space Management)?
Date: Mon, 3 Aug 2009 17:07:59 -0700 (PDT)
Do you use ASSM (Automatic Segment Space Management)? This feature was introduced in 9.2. The benefits are unclear - have anyone seen test results proving that in real-life situation ASSM produces improvements?
At the same time ASSM has so many bugs: slow performance, spin/hang, excessive space usage, space leaks, etc. Just search Metalink for ASSM. Almost all ASSM-related bugs are "private", i.e. no additional information is available.
Bug 7575925 – ASSM blocks may be marked with wrong “freeness” (private
Affected version: 10.2.0.4
Fixed in: 10.2.0.5, 11.2 (Future Release)
Bug 5728380 – DML may spin searching for space in ASSM (private bug) Affected versions: 22.214.171.124, 10.2.0.3
We had several instances where Apps Support would run large uncomitted DELETE (in different apps) and performance of single-row INSERT would deteriorate dramatically: from 10 buffer gets per INSERT to 100,000. Received on Mon Aug 03 2009 - 19:07:59 CDT